Method for forming photomask and photolithography method

A photomask repair method, comprising:

• forming a reflective layer over a substrate;
• forming a light-absorbing layer over the reflective layer, wherein the light-absorbing layer has a first portion, a second portion, and a connection portion, the connection portion is connected between the first portion and the second portion, and the second portion is over a third portion of the reflective layer;
• forming a mask layer over the first portion and the second portion of the light-absorbing layer;
• removing the connection portion of the light-absorbing layer;
• removing the mask layer, wherein the second portion of the light-absorbing layer is removed during removing the mask layer, while the first portion remains;
• removing the third portion of the reflective layer to form a recess in the reflective layer;
• and
• forming a light-absorbing structure in the recess.

A photolithography method, comprising:

• providing a photomask over a photoresist layer, wherein the photomask comprises:
• a substrate and a reflective layer over the substrate, wherein the reflective layer has a surface;
• a main light-absorbing structure over the surface;
• and
• an assist light-absorbing structure partially embedded in the reflective layer, wherein the assist light-absorbing structure has an upper portion and a lower portion, the lower portion is in the reflective layer, the upper portion protrudes away from the surface of the reflective layer, and a first top surface of the upper portion is higher than a second top surface of the main light-absorbing structure;
• and
• irradiating the photomask by a light, wherein the light is partially reflected to a first part of the photoresist layer by the reflective layer and is partially absorbed by the main light-absorbing structure and the assist light-absorbing structure.